JPH0452977Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ignition coil used in a vehicle engine, etc., and particularly to an ignition coil whose iron core can be made lighter and more compact.

[Prior art] In order to increase the output of the ignition coil,
It has already been proposed to insert a magnet that applies a reverse bias into the magnetic path formed in the iron core and use this as part of the input energy (see French Patent Publication Nos. 2,531,751 and 2,531,752).
According to this, it is also possible to make the iron core lighter and more compact in accordance with the reduction in the cross-sectional area of the magnetic path.

[Problems to be solved by the invention] By the way, as in the conventional structure described above, when a magnet is inserted into a part of the iron core, the magnet is broken by the vibration of the iron core. need to be protected from being Also, it is necessary to ensure that the magnet is not missing.

An object of the present invention is to provide an ignition coil that satisfies these points.

[Means for Solving the Problems] The ignition coil of the present invention includes an iron core formed in a closed loop via a magnet, and a primary coil and a secondary coil wound around the iron core. The magnet is disposed so as to apply a reverse bias to the closed magnetic path formed when the primary coil is energized, and is attached to one end surface of the iron core, and at least the connecting portion of the magnet and the iron core is It is characterized in that it is integrally attached with a coating resin that covers its periphery.

[Operation of the invention] The iron core of the ignition coil according to the invention is
A part of it is integrally covered with a coating resin together with the magnet. Therefore, it can be securely attached to the iron core, and there is no need for subsequent attachment work when assembling the ignition coil. Furthermore, even if the core vibrates during use, the magnet and core vibrate as one, making it difficult to break.

[Embodiment] The figure shows a cross section of an ignition coil, and a primary coil 2 and a secondary coil 3 are housed in a coil case 1 made of a suitable resin and having an opening at one end. The primary coil 2 is wound around a cylindrical primary coil bobbin 2a, and both ends of the primary coil bobbin 2a are opened to the opening and the bottom 1a of the coil case 1, and the hollow part is opened to the bottom 1a of the coil case 1.
It forms an iron core passageway that runs through the inside. Note that the primary coil bomb 2a and the bottom portion 1a are connected in a liquid-tight manner by an appropriate method. The coil case 1 is filled with a suitable resin 4 such as epoxy resin.

An arm portion 6 of a C-shaped iron core 5 passes through the hollow portion of the primary coil bobbin 2a. On the other hand, the other arm part 7 of the C-shaped core 5 extends outside the coil case 1 substantially parallel to the arm part 6, and has a dovetail groove 7a formed at its tip, and a dovetail groove 7a formed at one end of the type core 8. It is possible to fit into the tenon part 8a. Further, the length of the arm portion 7 is reduced by the width of the molded iron core 8. A magnet 10 is provided between the molded iron core 8 and the arm portion 6. magnet 10
is in contact with the end face of the mold core 8, and its periphery is integrated with a portion of the mold core 8 by a coating resin 11. The magnet 10 is installed so as to apply a reverse bias to a closed magnetic path formed within a C-type core constituted by a C-type core 5 and a C-type core 8.

To assemble this ignition coil, first, the magnet 10 is temporarily fixed to the end face of the mold core 8, and is fixed in a mold together with a portion of the mold core 8, and then integrally formed with a suitable resin. At this time, if necessary, the arm portion 6 of the magnet 10
It is also possible to cover even the side surfaces. Next, C
The arm part 6 of the type iron core 5 is attached to the bottom part 1 of the coil case 1.
It is passed through the hollow part of the primary coil bobbin 2a from the a side, and the tip part is made to protrude to the other end of the primary coil bobbin 2a. Furthermore, after that, the tenon part 8a at one end of the mold core 8 is fitted into the dovetail groove 7a of the arm part 7. As a result, the magnet 10 integrally attached to the other end of the molded iron core 8 is automatically pressed against the side surface of the arm portion 6. Thereafter, if necessary, the C-shaped core 5 and the shaped core 8 are clamped at the top and bottom by a frame member (not shown) to be reinforced and fixed. In this way,
C- which forms a loop shape from the C type iron core 5 and the type iron core 8.
When the loop-shaped core is constructed and the primary coil 2 is energized, a closed magnetic path is formed within the loop-shaped core. Moreover, since the magnet 10 is inserted into the closed magnetic circuit so as to apply a reverse bias, the magnetic energy of the magnet 10 can be used as input energy to the ignition coil.
As a result, it is possible to reduce the cross-sectional area of the magnetic path, making it possible to make the core lighter and more compact.

Moreover, since the magnet 10 is integrated with the molded iron core 8 in advance by the coating resin 11, there is no need to take the trouble to attach the magnet 10 when assembling the ignition coil, and the positioning for attaching the magnet 10 is very easy. Be easy and accurate. Furthermore, since the attachment is secure, there is less risk of it coming off during use. Furthermore, since the magnet 10 is protected by the resin coating and can vibrate at least integrally with the vibration of the iron core 8, there is little risk of it being destroyed by the molded iron core 8, and even if it is broken, fragments will not scatter. Easy to prevent.

[Effects of the invention] The ignition coil according to the invention has a coating resin that covers at least a part of the iron core.
The magnet is pre-integrated and installed. Therefore, the magnet and the core portion to which it is attached can vibrate together, so that the magnet can be prevented from being destroyed, and the magnet can be accurately positioned relative to the core. Moreover, since the installation is reliable, it is possible to prevent the parts from being removed during use.

[Brief explanation of the drawing]

The figure is a cross-sectional view of the ignition coil. Explanation of symbols, 1...Coil case, 2...Primary coil, 3...Secondary coil, 5...C type iron core, 8
...Type iron core, 10...Magnet, 11...Coating resin.

Claims (1)

[Scope of utility model registration request] An iron core forming a closed loop via a magnet,
In this ignition coil including a primary coil and a secondary coil wound around an iron core, the magnet is arranged to apply a reverse bias to a closed magnetic path formed when the primary coil is energized. The ignition coil is attached to one end surface of the iron core, and is integrally attached to at least a connecting portion of the magnet and the iron core with a coating resin covering the periphery thereof.